Projects / Programmes
Molecular mechanism of endogenous TLR4 agonist formation and its role in chronic inflammatory diseases
| Code |
Science |
Field |
Subfield |
| 3.01.00 |
Medical sciences |
Microbiology and immunology |
|
| Code |
Science |
Field |
| B000 |
Biomedical sciences |
|
| Code |
Science |
Field |
| 3.01 |
Medical and Health Sciences |
Basic medicine |
extracellular vesicles, oxidized phospholipids, oxidative stress, TLR4, rheumathoid arthritis
Researchers (13)
Organisations (2)
Abstract
Sterile inflammation occurs under acute conditions, such as ischemia/reperfusion or trauma, but it also underlies the pathologies of diseases characterized by chronic inflammatory conditions including atherosclerosis, autoimmune diseases, aging-related pathologies and cancer. The signaling pathways (TLRs and inflammasomes are the most studied) that sense infection also contribute to sterile inflammation by producing proinflammatory cytokines. Sterile inflammation is accompanied by oxidative stress, which contributes to injuries. Additionally, some enzymes among them lipoxygenases (LO) and phospholipase A2 (PLA2) are induced by stress and contribute to inflammation.
One of the main features of oxidative stress is increased peroxidation of phospholipids (PLs) thus defining them as potential danger associated molecules (named DAMPs). In this project we want to determine the molecular species of peroxidized PLs that activate TLR4/MD-2 complex and confirm their role in chronic diseases. Additionally, we want to elucidate the mechanism of endogenous ligand formation involving 15-LO and PLA2. This process will be further confirmed in clinical samples and in mice model of arthritis thus giving the project (patho)physiological relevance.
The basis for our hypothesis are preliminary results which show that 15-LO oxidized lysoPLs activate MD-2/TLR4 and that PLA2 releases oxidized lysoPLs from PL embedded in extracellular vesicles (EVs) thus resulting in TLR4 activity. According to this the main objectives of the project are:
Identification of the mechanism of TLR4/MD-2 agonist formation triggered by the oxidative stress and structural identification of activating agonists including identification of target phospholipids and their acylation pattern.
Identification of the binding mechanism of ox lysoPLs to MD-2 and TLR4.
Characterization of intracellular pathways and cytokine profile of TLR4 stimulation by EVs and ox lysoPLs in comparison to activation by LPS. Additionally, comparison of cytokine profiles between TLR4 agonists (LPS, lipidIVa, taxol and EVs) will be performed.
Quantification of secretory PLA2 activity in the synovial fluid samples from patients with RA and confirmation of its activity in formation of TLR4/MD-2 agonists.
Use of sPLA2-IIATGN mice to confirm the hypothesis and test PLA2 and 12-LO inhibitors in treatment of arthritis.
Although the project aims to demonstrate a new, unexpected mechanism of formation of TLR4 agonists, where the synergy between two PL processing enzymes is crucial, we have performed a significant number of experiments. Although they are preliminary in nature and will have to be repeated to reach the required certainty, results nevertheless confirm that the hypothesis is in fact correct. Therefore the feasibility of the project is high despite the originality of this innovative concept. Qualifications of the PI in the project area and other project team members provide broad expertise and links to most relevant international partners. Together they are an excellent foundation to successfully fulfill this project.
Significance for science
Inflammatory diseases, where TLR receptors are involved, and lipid oxidation are between main causes of death as they are involved in cardiovascular to autoimmune diseases. How and why inflammation develops and what are endogenous ligands is still detrimental, although knowledge on molecular mechanisms is prerequisite for development of efficient therapies and diagnostics.
Collaboration with other groups also from abroad enables us to work on clinically important issues by using synovial fluid samples from patients and animal models of arthritis, where the results and clinical picture can have direct influence on patient´s treatment.
Publishing of scientific papers and successful application of research of those diseases will broaden our knowledge on chronic diseases. Understanding of the molecular mechanisms is not only of medical, but also of biotechnological importance. The results could lead to development of new approaches and tools for disease diagnostic. By pointing out the differences between sterile and classical innate immune response we will also expose points of possible therapeutic intervention.
Using innovative strategies and new ideas we will educate students (undergraduate and PhD students) for research and will pass our knowledge to scientific community through international workshops and conferences.
Significance for the country
Inflammatory diseases, where TLR receptors are involved, and lipid oxidation are between main causes of death as they are involved in cardiovascular to autoimmune diseases. How and why inflammation develops and what are endogenous ligands is still detrimental, although knowledge on molecular mechanisms is prerequisite for development of efficient therapies and diagnostics.
Collaboration with other groups also from abroad enables us to work on clinically important issues by using synovial fluid samples from patients and animal models of arthritis, where the results and clinical picture can have direct influence on patient´s treatment.
Publishing of scientific papers and successful application of research of those diseases will broaden our knowledge on chronic diseases. Understanding of the molecular mechanisms is not only of medical, but also of biotechnological importance. The results could lead to development of new approaches and tools for disease diagnostic. By pointing out the differences between sterile and classical innate immune response we will also expose points of possible therapeutic intervention.
Using innovative strategies and new ideas we will educate students (undergraduate and PhD students) for research and will pass our knowledge to scientific community through international workshops and conferences.
Most important scientific results
Interim report
Most important socioeconomically and culturally relevant results
